WO2023165669A1

WO2023165669A1 - Biocrude production system

Info

Publication number: WO2023165669A1
Application number: PCT/DK2023/050034
Authority: WO
Inventors: Ib Johannsen; Christoffer Riis JENSEN
Original assignee: Circlia Nordic Aps
Priority date: 2022-03-02
Filing date: 2023-03-02
Publication date: 2023-09-07

Abstract

A biocrude production system (SYS) is disclosed, the system comprising a plurality of decentral hydrothermal liquefaction units (HTLU) and a central controlling facility (CCF), each hydrothermal liquefaction unit (HTLU) comprising a pressurizing unit (PRU) configured for pressurizing a biomass, a heating unit (HEU) arranged heat the biomass, and a hydrothermal liquefaction reactor (HLR) arranged to convert the biomass to into biocrude, each hydrothermal liquefaction unit (HTLU) having a local operating system and being communicatively coupled with the central controlling facility (CCF), the operating system being configured to control the hydrothermal liquefaction unit (HTLU) in accordance with a set of operational parameters, wherein a first subset of said operational parameters is controllable by said central controlling facility, and wherein a second subset of said operational parameters is controllable exclusively by the local operating system. Also disclosed is a method of operating a plurality of decentral hydrothermal liquefaction units and a computer program product.

Description

BIOCRUDE PRODUCTION SYSTEM FIELDS OF INVENTION The invention relates to a biocrude production system according to the claims, a method for operating hydrothermal liquefaction units according to the claims, and a computer program product according to the claims. BACKGROUND Finding replacements for fossil fuels such as fossil crude oil has become increasingly important. Using high temperature and pressure to convert biomass by means of hydrothermal liquefaction has the benefit of being relatively efficient in converting the biomass. However, due to the processing conditions necessary, building efficient and safe hydrothermal liquefaction based biocrude production system is a challenge. SUMMARY The invention relates to a biocrude production system comprising a plurality of decentral hydrothermal liquefaction units and a central controlling facility, each hydrothermal liquefaction unit comprising a pressurizing unit configured for pressurizing a biomass, a heating unit arranged heat the biomass, and a hydrothermal liquefaction reactor arranged to convert the biomass to into biocrude, each hydrothermal liquefaction unit having a local operating system and being communicatively coupled with the central controlling facility, the operating system being configured to control the hydrothermal liquefaction unit in accordance with a set of operational parameters, wherein a first subset of said operational parameters is controllable by said central controlling facility, and wherein a second subset of said operational parameters is controllable exclusively by the local operating system. An advantage of the invention may be that by controlling the first subset of operational parameters by the central controlling facility, a more efficient biocrude production system may be obtained, e.g. with respect to obtaining an improved and cost-efficient conversion of biomass to biocrude, minimizing down time etc. Particularly, by using a central controlling facility which can control the first subset of operational parameters, an increased optimization both with respect to the joint operation of the system may be obtained and also with respect to external factors. Increased optimization with respect to the joint operation of the system may involve an improved operational timing between the individual hydrothermal liquefaction units. This may involve more evenly distribution of collection of biocrude and other output stream components. Similarly, it may involve a more evenly distribution of biomass deliveries when the biomass is supplied externally from the hydrothermal liquefaction units. This may decrease the load on transportation capacity and avoid undesirable shutdown due to lack of storage capacity or lack of biomass at the hydrothermal liquefaction units. Also, by synchronizing scheduled maintenance, undesirable shutdowns due to lack of sufficient maintenance staff may be avoided. Also, increased optimization with respect to external factors may involve increased possibilities of taking into account factors such as pricing fluctuation, such as power pricing, additive pricing, biomass pricing, expected external demand, expected supply, etc. As an example, if a power pricing surge is detected or expected by the central controlling facility, it may prompt a temporary shutdown of some or even all of the hydrothermal liquefaction units. Another advantage of the invention may be that a more efficient biocrude production system may be obtained while ensuring sufficient resilience of the system. By reserving a second subset of operational parameters for the exclusive control of the local operating system, the system may be more robust against undesirable side effects of operating by a central controlling system. For example, when using the internet for communication, a small albeit increasing risk may exist of undesirable third party interventions. Having a local control of the second subset ensures that even if such a third party is successful in instructing the decentral hydrothermal liquefaction units to operate in a way that may risk inflicting damage on the units, this may be overruled by local intervention. Such local intervention may include activating override protection or activating emergency pressure reduction measures. Also, if the connection between the central control facility and the hydrothermal liquefaction units becomes unstable, this may lead to a risk that instructions sent from the central control facility are so unadopted to the actual conditions at the units that undesirable situations may arise. In such situations, it may be desirable that override protection may be activated to ensure local control until proper communication has been reestablished. Also, certain undesirable situations may arise locally, which the central controlling facility may not necessarily detect, e.g. if no sensors are installed to detect the fault or if such sensors are malfunctioning. In such situation, activation of override protection may be highly advantageous to keep the central controlling facility to unknowingly operate the hydrothermal liquefaction unit in an undesirable way. Additionally, some undesirable situations may arise quickly and/or need immediate rectification. In such situations, it may be advantageous to activate override protection for parameters. In particular, undesirable and/or unexpected evolution in pressure, particularly pressure surges, may require immediate deactivation of pressurizing units, heating units and/or activation of pressure relief valves. A further advantage of the invention may be that by allowing a relatively efficient operation of a plurality of decentral hydrothermal liquefaction units, a complicated logistical setup may be avoided, as transportation of raw biomass may be avoided by decentral processing. For example, since the aqueous fractions containing the biomass may typically be composed mostly of water with only some biomass, the volume to be transported may be significantly reduced by local processing into biocrude and separation of water before transportation of the biocrude instead of transporting the aqueous biomass containing fractions. In the present context the term “decentral hydrothermal liquefaction units” refers to hydrothermal liquefaction units which are not all located at the same site. Thus, the hydrothermal liquefaction units are distributed at a plurality of sites. In some embodiments, at least one site has two or more hydrothermal liquefaction units. In some embodiments, the site of the central controlling facility also comprises a hydrothermal liquefaction unit. In the present context, the term “hydrothermal liquefaction” refers to a process of decomposition of wet biomass at high temperatures and pressure. The wet biomass is biomass mixed with water, e.g. with a water content of above 50% by weight, such as 50-90% by weight. The wet biomass may also comprise other components, additives etc. The wet biomass, i.e. the input to the hydrothermal liquefaction unit may also be referred to as feedstock. Typically, the applied temperatures during hydrothermal liquefaction range from 250 to 450 degree Celsius, such as 300 to 425 degrees Celsius. Also, the applied pressure during hydrothermal liquefaction ranges from 50 to 400 bar, such as 100 to 300 bar. In the present context the term “central controlling facility” refers to a controlling facility which is centralized in the sense that the controlling facility is common for the plurality of decentral hydrothermal liquefaction units. Also, while the central controlling facility is configured to control the first subset of said operational parameters, the central controlling facility is also in some embodiments configured to monitor one or more of the plurality of decentral hydrothermal liquefaction units or a part thereof, e.g. with respect to one or more operational parameters of the hydrothermal liquefaction units. In the present context it should be understood that when referring to each hydrothermal liquefaction unit this refers to each of said plurality of hydrothermal liquefaction units. In the present context, the term operational parameter refers to a control parameter which is a control input to the hydrothermal liquefaction units, and thus influences the operation of the hydrothermal liquefaction units. Such influence may not necessarily be active all the time, particularly if the operational parameter relates to emergency measures, which are only rarely activated if at all. Therefore, the influence on the operation includes both continuous influence, occasional influence, and even hypothetical influence in the sense that it may only be activated under certain defined circumstances which may or may not arise for the particular hydrothermal liquefaction unit. In the present context, the first subset of said operational parameters are controllable by the central controlling facility, i.e. such that the operational parameters are adjustable based on signals transmitted from the central controlling facility. E.g., the central controlling facility may set of the value of the first subset of said operational parameters. It is noted that that the first subset of operational parameters may comprise operational parameters, which are controllable exclusively by the central controlling facility and may comprise operational parameters, which are controllable by both the central controlling facility and the respective local operating system. In some embodiments, a third subset of said operational parameters are controllable by said central controlling facility and by said local operating system. In the present context the term “pressurizing unit” refers to a unit for pressurizing the input stream including the biomass. The pressurizing unit may be any kind of suitable pressurizer, such as one or more high-pressure pumps or similar arrangement. In the context of the present invention, a local operating system is understood as a system comprising both hardware components including one or more central processing units (CPUs) and a memory, and software capable of being executed on the hardware. The software ensures that the processes of the local operating system run according so suitable algorithms. The local operating system may further comprise one or more input/output controllers for receiving and processing input from any number of electronic input devices, such as a keyboard, a mouse, a touchpad, a touch screen, or any other type of electronic input device. Similarly, the input/output controllers may provide output to a display, such as a computer monitor, a flat-panel display, one or more lights, a printer, or any other type of electronic output device. The local operating system may comprise a graphical user interface (GUI) facilitating interactions with a user of the local operating system. In the context of the present invention the term “communicatively coupled” is understood such that a data communication channel (or communication link) is facilitated between the local operating system and the central monitoring facility for the purpose of transmission and reception of electronic communication, e.g., data communication, between the local operating system and the central monitoring facility. The communicatively coupling of the local operating system and the central monitoring facility facilitates at least the possibility of the central monitoring facility transmitting instructions for controlling an operational parameter relating to a hydrothermal liquefaction unit. As an example, the central monitoring facility may transmit a request for the local operating system to change/update an operational parameter of the hydrothermal liquefaction unit. In an advantageous embodiment of the invention, the local operating system is arranged to receive a first subset operational parameter instruction sent by the central controlling facility. The first subset operational parameter instruction is an instruction to set an operational parameter of the first set of operational parameters to a given value. In an advantageous embodiment of the invention, the set of operational parameters comprise at least one operational parameter of one or both of the pressurizing unit and the heating unit. In an advantageous embodiment of the invention, the first subset of operational parameters comprises at least one operational parameter of one or both of the pressurizing unit, the heating unit. An advantage of the above embodiment may be that a more efficient processing may be obtained by allowing the central controlling facility to set control parameters of one or both of the pressurizing unit and the heating unit. Particularly, by controlling facilitating a desirable pressure and temperature, the conversion of biomass into biocrude may be controlled to yield a desirable result. In an embodiment of the invention, a third subset of said operational parameters are controllable by said central controlling facility and by said local operating system, the third subset comprising at least one operational parameter of one or both of the pressurizing unit, the heating unit. An advantage of the above embodiment may be that the hydrothermal liquefaction units may continue to operate even if the connection to the central controlling facility is temporarily lost. In an advantageous embodiment of the invention, each hydrothermal liquefaction unit further comprises a depressurizing unit for depressurizing the biocrude, and wherein the first subset of operational parameters comprises at least one operational parameter of one or more of the pressurizing unit, the heating unit, and the depressurizing unit. In an embodiment of the invention, each hydrothermal liquefaction unit further comprises a depressurizing unit for depressurizing the biocrude, and wherein the third subset of operational parameters comprises at least one operational parameter of one or more of the pressurizing unit, the heating unit, and the depressurizing unit. In an advantageous embodiment of the invention, the first subset of operational parameters comprises or relate to at least one selected from the group consisting of pressure of the biomass before the pressurizing unit, the degree of oscillatory flow in the hydrothermal liquefaction reactor, the heating profile, separation control parameters, heat exchange control parameters, pressurizing parameters, depressurizing parameters, gas cleaning parameters, pressure relief valve control parameters, and any combination thereof. In an advantageous embodiment of the invention, the second subset comprises one or more emergency shutdown operational parameters. An advantage of the above embodiment may be a more safe and robust operation, due to the at least one or more emergency shutdown operational parameters being reserved for control by the local operating system without any input from the central control facility. Therefore, even if control input received from the central control facility would result in hazardous situations, the local operating system is able to prevent this by initiating the controlling the one or more emergency shutdown operational parameters. The first subset may comprise further emergency shutdown operational parameters. In an embodiment of the invention, the set of operational parameters comprises one or more parameter related to the group consisting of pressure in the hydrothermal liquefaction reactor, temperature in the hydrothermal liquefaction reactor, residence time in the hydrothermal liquefaction reactor, and any combination thereof. In an embodiment of the invention, the set of operational parameters comprises one or more parameters related to the pressure in the hydrothermal liquefaction reactor. The pressure applied in the hydrothermal liquefaction reactor may depend on several factors, in particular the operation of the pressurization unit. Also, it may typically depend on the operation of a depressurization unit for decreasing the pressure after the hydrothermal liquefaction reactor. In an embodiment of the invention, the set of operational parameters comprises one or more parameters related to the temperature in the hydrothermal liquefaction reactor. The temperature applied in the hydrothermal liquefaction reactor may depend on several factors, in particular the operation of the heating unit. It may also be influenced by further factors, such as any preheating. In an advantageous embodiment of the invention, the second subset comprises an override protection setting. In the above embodiment, the override protection setting is controllable exclusively by the local operating system. When active, the override protection setting prevents setting of the protected operational parameter, particularly for preventing override from the central controlling facility. The override protection setting may cover one or more of the operational parameters. In an embodiment, the override protection covers all operational parameters for the hydrothermal liquefaction unit in question. An advantage of the above embodiment may be a more safe and robust operation. Even if control input received from the central control facility would result in hazardous situations, the local operating system is able to prevent or mitigate this by initiating the override protection setting. In an advantageous embodiment of the invention, the second subset comprises a setting of one or more pressure relief valves. An advantage of the above embodiment may be a more safe and robust operation. Even if control input received from the central control facility would result in hazardous situations, the local operating system is able to prevent or mitigate this by operating the one or more pressure relief valves. In an advantageous embodiment of the invention, the hydrothermal liquefaction units further comprise an input storage arranged to store biomass for processing in the hydrothermal liquefaction units. In an advantageous embodiment of the invention, at least one operational parameter relates to the input storage. In an advantageous embodiment of the invention, the hydrothermal liquefaction units further comprise an output storage arranged to receive biocrude produced in the hydrothermal liquefaction units. In an advantageous embodiment of the invention, at least one operational parameter relates to the output storage. In an advantageous embodiment of the invention, the first subset comprises at least one parameter related to transportation of the biocrude from the output storage. In an advantageous embodiment of the invention, the plurality of decentral hydrothermal liquefaction units comprises at least 3 hydrothermal liquefaction units, such as at least 5 hydrothermal liquefaction units, such as at least 10 hydrothermal liquefaction units, such as at least 20 hydrothermal liquefaction units, such as at least 50 hydrothermal liquefaction units. In an embodiment of the invention, the plurality of decentral hydrothermal liquefaction units comprises 3 to 200 hydrothermal liquefaction units, such as 5 to 150 hydrothermal liquefaction units, such as 10 to 100 hydrothermal liquefaction units, such as 20 to 100 hydrothermal liquefaction units, such as 50 to 100 hydrothermal liquefaction units. In an advantageous embodiment of the invention, each hydrothermal liquefaction unit further comprises a pre-treatment unit for processing said biomass. The pre-treatment unit may include one or more of lowering the water content (i.e. increasing the relative content of organic solids), heating the wet biomass to a pre- treatment temperature, increasing the pressure of the wet biomass to a pre-treatment pressure, addition of additives, etc. In an advantageous embodiment of the invention, each hydrothermal liquefaction unit further comprises a depressurizing unit for depressurizing the biocrude. In the present context it should be understood that the depressurizing of the biomass may be stepwise, and that the depressurizing unit of the above embodiment therefore may depressurize the biocrude in the sense that the pressure is lowered to a pressure that may be higher than atmospheric pressure. The depressurizing unit may also be referred to as a pressure let down unit, and may be configured to lower the pressure to below 50 bar, such as below 20 bar, such as below 5 bar, such as below 2 bar. In an advantageous embodiment of the invention, each hydrothermal liquefaction unit further comprises a separation unit for separating biocrude from other components. In the present context it should be understood that said other components includes at least water, but may also often include components inorganic solid fractions, sometimes also referred to as ash-fractions. Also, gasses produced in the processing of biomass into biocrude, hereunder carbon dioxide, may in some cases need to be separated. Often, biocrude, water, and gasses may be separated by means of a three- phase separation system, whereas inorganic solid fractions may be separated in a separate unit, e.g. comprising filtering, rotational and/or gravitational separation, etc. It is furthermore understood that hydrothermal liquefaction unit may include further units according to the specific design of the hydrothermal liquefaction unit. This may both be influenced by the capacity of the individual hydrothermal liquefaction unit, the input feedstock, the desired output biocrude etc. Also, one or more heat exchangers may be installed to increase energy efficiency. In an advantageous embodiment of the invention, the wet biomass has temperature in the hydrothermal liquefaction reactor within a range from 250 to 450 degrees Celsius, such as from 300 to 425 degrees Celsius. In an advantageous embodiment of the invention, the wet biomass has pressure in the hydrothermal liquefaction reactor within a range of 50 to 400 bar, such as 100 to 300 bar. In an advantageous embodiment of the invention, the wet biomass has a residence time within the hydrothermal liquefaction reactor within a range of at least 300 seconds up to 300 minutes. In an advantageous embodiment of the invention, the local operating system is communicatively coupled with the central monitoring facility via a communication channel. In the context of the present invention, a communication channel is understood as an electronic communication link. The communication channel may be facilitated by any electronic data communication technology capable of either one-way or two-way data communication between the central monitoring facility and the local operating system may be used. The data communication channel may communicate through hardware components facilitating an interface between the local operating system and the communication channel and between the communication channel and the central monitoring facility. Such interfaces may form part of the local operating system and the central monitoring facility. In an advantageous embodiment of the invention, the communication channel comprises a web service, such as the internet. An advantageous embodiment uses web service technologies or similar to establish the communication channel, for example and preferably via the public internet (or simply put “the internet”). In an advantageous embodiment of the invention, the communication channel comprises a wireless and/or a wired communication channel. By a wired communication channel is understood a communication system where there exists a physical media in the path between end points of the communication channel between the transceivers, or transmitter/receiver, communicating. The communication in a wired communication channel may be facilitated by electronic means (e.g. wires) and/or optical means (e.g. optical fibers). By a wireless communication is understood any type of communication based on a wireless communication protocol. Suitable wireless communication protocols include, but is not limited to, RF (Radio Frequency), 3G, 4G (LTE), and 5G. The skilled person would readily appreciate that the communication channel may comprise both a wireless communication channel and a wired communication channel as parts of the communication channel. In an advantageous embodiment of the invention, the communication channel comprises encryption means for encrypting data communications. By encryption means is understood any type of encryption capable of encrypting a data communication such as transport layer security (TLS), i.e., HTTPS, or suitable alternatives, or by encryption of the data themselves, e.g., encrypted XML or secure SOAP. In an advantageous embodiment of the invention, the system further comprises a central processing facility for receiving one or more product streams from the hydrothermal liquefaction units. In an embodiment of the invention, the system further comprises a central processing facility for receiving one or more product streams from one or more of the hydrothermal liquefaction units. In an advantageous embodiment of the invention, said one or more product streams comprises at least one of biocrude, carbon dioxide, and phosphate from the hydrothermal liquefaction units. In an advantageous embodiment of the invention, the central controlling facility is arranged to receive biocrude from the hydrothermal liquefaction units. In an advantageous embodiment of the invention, the central processing facility comprises a biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units. In an advantageous embodiment of the invention, biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units by lowering the viscosity of the biocrude, lowering oxygen content of the biocrude, increasing stability of the biocrude, increasing pumpability of the biocrude, increasing filterability of the biocrude, increase compatibility with oil refineries, mixing and/or homogenizing the biocrude, adapting for use as a bunker fuel, and any combination thereof. In embodiment where mixing and/or homogenizing of the biocrude is employed, the biocrude may be mixed with additives or may be mixed with other biocrudes to obtain biocrude having a uniform quality. The uniform quality may be understood as having a consistent quality over time, whereby the biocrude may be processed in a similarly consistent way. In an embodiment of the invention, improving the quality of the biocrude involves lowering the viscosity of the biocrude. In an embodiment of the invention, the system further comprises a viscosity lowering unit configured to lower the viscosity of biocrude received from the hydrothermal liquefaction units. In an embodiment of the invention, the biocrude processing unit is configured to process the biocrude in order to lower the oxygen content, lower the nitrogen content, remove inorganic salts, remove water, esterify the biocrude, or any combination thereof. In an embodiment of the invention, improving the quality of the biocrude involves increasing the stability of the biocrude. In an advantageous embodiment of the invention, the central processing facility comprises a gas cleaning unit configured to clean a carbon dioxide containing gaseous fraction from one or more of the hydrothermal liquefaction units. In an embodiment of the invention, the gas cleaning unit is configured to remove sulfuric compounds from the gaseous fraction. In an advantageous embodiment of the invention, the gas cleaning unit is located at the central controlling facility. In an alternative embodiment the gas cleaning unit is decentrally located, e.g. at each hydrothermal liquefaction unit. In an embodiment of the invention, the central processing facility is a distributed facility having at least one gas cleaning unit located at a different site than the rest of the facility. In an advantageous embodiment of the invention, the system further comprises a solid processing unit configured to improve the quality of a phosphate containing fraction received from one or more of the hydrothermal liquefaction units. In an embodiment of the invention, the solid processing unit is configured to improve the quality of the phosphate containing fraction by at least one of removing heavy metals, removing residual biocrude, and any combination thereof In an advantageous embodiment of the invention, the solid processing unit is located at the central controlling facility. In an advantageous embodiment of the invention, the central processing facility is co- located with said central control facility. In an embodiment of the invention, the central processing facility comprises two or more processing units. In an embodiment of the invention, said two or more processing units are co-located. In an embodiment of the invention, said two or more processing units located at different sites. Thus, in this embodiment the central processing facility is a distributed facility. In an advantageous embodiment of the invention, the central processing facility comprises a biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units, wherein the biocrude processing unit is co-located with said central control facility. In an advantageous embodiment of the invention, the hydrothermal liquefaction unit further comprises at least one sensor arranged to measure a process state parameter. In the present context it should be understood that process state parameters or state parameters are measured values at the hydrothermal liquefaction unit. Thereby, the state parameter reflects the state of the hydrothermal liquefaction unit or a part thereof. The state parameters are distinguished from operational parameters, which are control parameters, however, the operational parameters and state parameter may relate to the same parameter, such as e.g. a temperature, which may both be a set target value for the heating unit (i.e. an operational parameter) or may be a measured value (i.e. a state parameter) which is of course influenced by the corresponding operational parameter temperature, but not necessarily identical. In an advantageous embodiment of the invention, the hydrothermal liquefaction unit comprises at least one sensor arranged to measure one or more of a temperature, a pressure, and a flow parameter. In an embodiment of the invention, the hydrothermal liquefaction unit comprises at least one temperature sensor arranged to measure a temperature in the hydrothermal liquefaction unit, particularly in the hydrothermal liquefaction reactor. In an embodiment of the invention, the hydrothermal liquefaction unit comprises at least one pressure sensor arranged to measure a pressure in the hydrothermal liquefaction unit, particularly in the hydrothermal liquefaction reactor. In an embodiment of the invention, the hydrothermal liquefaction unit comprises at least one flow sensor arranged to measure a flow parameter in the hydrothermal liquefaction unit, particularly in the hydrothermal liquefaction reactor. In an embodiment of the invention, the hydrothermal liquefaction unit further comprises at least one sensor arranged to measure a process state parameter related to one or more of the pressurizing unit, the heating unit, and the processing unit. In an advantageous embodiment of the invention, the hydrothermal liquefaction unit is configured to communicate said process state parameter to the central control facility. In an advantageous embodiment of the invention, the hydrothermal liquefaction unit is configured to measure and communicate said process state parameter to the central control facility automatically. Thus, in the above embodiment, the hydrothermal liquefaction unit will during operation automatically measure said process state parameters, preferably by means of the at least one sensor. Furthermore, the measured process state parameter is automatically communicated to the central controlling facility. This means that said process state parameter may be measured and communicated to the central controlling facility automatically. In some embodiments, a number of process state parameters are measured, whereas only one or some but not all are communicated to the central controlling facility. In some embodiments, all measured process state parameters are communicated to the central controlling facility. In some embodiments, one or more of the measured process state parameters are used to calculate a further parameter which is communicated to the central controlling facility. In some embodiments, the one or more process state parameters and/or further parameter(s) are communicated to the central controlling facility at predetermined time periods. In an advantageous embodiment of the invention, the central controlling facility is configured to control the first subset of operational parameters at least partly based on the process state parameter. In an advantageous embodiment of the invention, the central controlling facility is configured to automatically control the first subset of operational parameters. In an advantageous embodiment of the invention, the central controlling facility is configured to automatically control the first subset of operational parameters at least partly based on the process state parameter. The invention further relates to a method for operating a plurality of decentral hydrothermal liquefaction units, the method comprising the steps of providing a biomass at each hydrothermal liquefaction unit, pressurizing said biomass at each hydrothermal liquefaction unit, heating said biomass at each hydrothermal liquefaction unit, transmitting a first subset of operational parameters from a central controlling facility to each hydrothermal liquefaction unit operating each hydrothermal liquefaction unit in accordance with a set of operational parameters comprising said first subset and a second subset, wherein the second subset is controllable exclusively by a local operating system of each hydrothermal liquefaction unit. In an advantageous embodiment of the invention, the plurality of decentral hydrothermal liquefaction units forms part of the biocrude production system according to the invention or any of its embodiments. The invention further relates to a computer program product comprising instructions that when executed by a computer processor of a central controlling facility of the biocrude production system according to the invention or any of its embodiments carries out the method according to the invention or any of its embodiments. FIGURES The invention will now be described with reference to the figures, where Figure 1A illustrates a biocrude production system SYS according to an embodiment of the invention, Figure 1B illustrate a hydrothermal liquefaction unit HTLU according to an embodiment of the invention, Figure 2 illustrate a hydrothermal liquefaction unit HTLU according to an embodiment of the invention, and Figure 3 illustrates a biocrude production system SYS according to an embodiment of the invention.

DETAILED DESCRIPTION Referring to figures 1A and 1B, a biocrude production system SYS according to an embodiment of the invention is illustrated. As shown in figure 1A, the system comprises a plurality of decentral hydrothermal liquefaction units HTLU1-HTLU10 and a central controlling facility CCF. The central controlling facility CCF is arranged to be communicatively coupled to each of the hydrothermal liquefaction units HTLU1-HTLU10, specifically the local operating system of each hydrothermal liquefaction unit. As illustrated the central controlling facility CCF can sent instructions INS to the hydrothermal liquefaction units HTLU1- HTLU10. An example of a hydrothermal liquefaction unit HTLU is shown in figure 1B. The hydrothermal liquefaction unit HTLU comprises a pressurizing unit PRU, a heating unit HEU, and a hydrothermal liquefaction reactor HLR. The hydrothermal liquefaction unit HTLU receives an input stream IPS comprising wet biomass BM which is converted into an output stream OPS comprising biocrude BCR. It is noted that the input stream comprises water, biomass, and in some emboidments further components, such as additives etc. The input stream may also often contain some level of inorganic solid components; however, these are not desired and if possible are eliminated or lowered before feeding the input stream to the hydrothermal liquefaction unit. As used herein, the term input stream is used also for the stream after being partially processed until the hydrothermal liquefaction reactor HLR. Conversely, the output stream comprises biocrude, water and typically also other components, such as carbon dioxide. The output stream may also comprise undesirable components, such as inorganic solid components. Herein, the term output stream is used to denote the output of the hydrothermal liquefaction reactor HLR. The output stream may then be processed until the biocrude is separated from the output stream. The pressurizing unit PRU is configured to pressurize the received input stream IPS, whereas the heating unit HEU is configured to heat the input stream IPS. The applied pressure of the pressurizing unit PRU together with the temperature obtained by means of the heating unit HEU should be high enough to allow thermal decomposition of the biomass in the subsequent hydrothermal liquefaction reactor HLR, where the biomass BM is converted to into biocrude BCR. Furthermore, each hydrothermal liquefaction unit HTLU has a local operating system. The operating system is configured to control the hydrothermal liquefaction unit HTLU in accordance with a set of operational parameters. As shown in figure 1A, the hydrothermal liquefaction units HTLU1-HTLU10 are communicatively coupled with the central controlling facility CCF. Thus, the hydrothermal liquefaction units HTLU1-HTLU10 may receive instructions INS from the central controlling facility, whereby some of the operational parameters may be set. In particular, the operational parameters comprise a first subset, which is controllable by said central controlling facility, and a second subset, which is controllable exclusively by the local operating system. Thus, the first subset of operational parameters is controllable by the central controlling facility. In some embodiments, the first subset relates to operational parameters of normal operation, whereas the second subset relates to operational parameters of extraordinary operation, such as emergency procedures and emergency shutdown. In one embodiment, the hydrothermal liquefaction units HTLU1-HTLU10 operate exclusively on instructions received from the central controlling facility, as long as the communicative connection is retained. During connection fallouts, the hydrothermal liquefaction units HTLU1-HTLU10 may advantageously switch to a local operational mode. This may e.g. be done by having main operating parameters included in a third subset of said operational parameters being controllable by said central controlling facility CCF and by said local operating system. While the hydrothermal liquefaction units HTLU1-HTLU10 operate exclusively on instructions received from the central controlling facility, some emergency measures may be controllable exclusively by the local operating system. Such emergency measures may e.g. include emergency pressure reduction measures such as activation of relief valves. Referring to figure 2, a hydrothermal liquefaction unit HTLU according to an embodiment of the invention is illustrated. The hydrothermal liquefaction unit HTLU comprises, in addition to the units shown in figure 1B, a pre-treatment unit PTU, a heat exchanger HEX, a solid-liquid separator SLS, a depressurization unit DPU, and a three-phase separator TPS. Also, the hydrothermal liquefaction unit HTLU comprises an input storage IST and an output storage OST. In some embodiments the input storage IST and/or the output storage OST is positioned externally from the hydrothermal liquefaction unit HTLU. In figure 2, the pretreatment unit PTU is shown as a part of the hydrothermal liquefaction unit HTLU. In some other embodiments, the wet biomass may be pretreated externally from the hydrothermal liquefaction unit HTLU in addition to or as an alternative to the internal pretreatment unit PTU of figure 2. The pretreatment may typically involve mixing with certain additives, heating to a pretreatment temperature, reduction of water content, filtering of inorganic solid material, reduction of particle size of the wet biomass, etc. In the embodiment of the figure 2, the hydrothermal liquefaction unit HTLU receives the input stream IPS and stores the wet biomass in the input storage IST, whereafter it is forwarded to the pretreatment unit PTU. In figure 2, the hydrothermal liquefaction unit HTLU comprises two separation units, namely the solid-liquid separator and the three-phase separator TPS. Other embodiments may include only one separation unit or may contain additional separation units. The embodiment illustrated in figure 2, however, illustrates an advantageous way of establishing main separation processes. The solid-liquid separator SLS may preferable be arranged before the depressurization unit DPU to operate at increased temperature and pressure of the output stream. This way, solids SOL may effectively be removed or at least lowered to an acceptable level. Solid-liquid separators may e.g. include filtering and/or rotational separation, such as hydrocyclones. The depressurization unit DPU is configured to lower the pressure of the output stream. In some embodiments, the pressure may be lowered to ambient pressure. In some embodiments, the pressure may be lowered to a pressure, which is higher than ambient, but still lower than the pressure of the hydrothermal liquefaction reactor HLR. The tree-phase separator TPS, preferably positioned after the depressurization unit DPU, is arranged to separate the product stream into a gaseous phase e.g. comprising carbon dioxide, an aqueous stream AQS mainly composed of water, and a stream comprising biocrude. As shown in figure 2, the produced biocrude BCR may be stored in an output storage OST before being discharged from the hydrothermal liquefaction unit HTLU. Now turning to figure 3, a biocrude production system SYS according to an embodiment is illustrated. As shown, the system comprises five hydrothermal liquefaction units HTLU1- HTLU5. Also, the system comprises a central controlling facility CCF and a central processing facility CPF, which have a shared location SHL. The hydrothermal liquefaction units HTLU1-HTLU5 receive instructions INS from the central controlling facility, as also illustrated in connection with the embodiment of figure 1. The central processing facility CPF receives one or more product streams PST from the hydrothermal liquefaction units HTLU1-HTLU5, e.g. one or more of biocrude, carbon dioxide, and phosphate. The one or more product streams may be transported to the central processing facility CPF by means of one or more pipelines or by cargo transportation, e.g. by truck or train.

Claims

CLAIMS 1. A biocrude production system (SYS) comprising a plurality of decentral hydrothermal liquefaction units (HTLU) and a central controlling facility (CCF), each hydrothermal liquefaction unit (HTLU) comprising a pressurizing unit (PRU) configured for pressurizing a biomass, a heating unit (HEU) arranged heat the biomass, and a hydrothermal liquefaction reactor (HLR) arranged to convert the biomass to into biocrude, each hydrothermal liquefaction unit (HTLU) having a local operating system and being communicatively coupled with the central controlling facility (CCF), the operating system being configured to control the hydrothermal liquefaction unit (HTLU) in accordance with a set of operational parameters, wherein a first subset of said operational parameters is controllable by said central controlling facility, and wherein a second subset of said operational parameters is controllable exclusively by the local operating system.

2. The biocrude production system (SYS) according to claim 1, wherein the local operating system is arranged to receive a first subset operational parameter instruction (INS) sent by the central controlling facility.

3. The biocrude production system (SYS) according to claim 1 or 2, wherein the set of operational parameters comprise at least one operational parameter of one or both of the pressurizing unit (PRU) and the heating unit (HEU).

4. The biocrude production system (SYS) according to any of claims 1-3, wherein the first subset of operational parameters comprises at least one operational parameter of one or both of the pressurizing unit (PRU), the heating unit (HEU).

5. The biocrude production system (SYS) according to any of claims 1-4, wherein each hydrothermal liquefaction unit further comprises a depressurizing unit for depressurizing the biocrude, and wherein the first subset of operational parameters comprises at least one operational parameter of one or more of the pressurizing unit (PRU), the heating unit (HEU), and the depressurizing unit (DPU).

6. The biocrude production system (SYS) according to any of claims 1-5, wherein the first subset of operational parameters comprises or relate to at least one selected from the group consisting of pressure of the biomass before the pressurizing unit, the degree of oscillatory flow in the hydrothermal liquefaction reactor, the heating profile, separation control parameters, heat exchange control parameters, pressurizing parameters, depressurizing parameters, gas cleaning parameters, pressure relief valve control parameters, and any combination thereof.

7. The biocrude production system (SYS) according to any of claims 1-6, wherein the second subset comprises one or more emergency shutdown operational parameters.

8. The biocrude production system (SYS) according to any of claims 1-7, wherein the second subset comprises an override protection setting.

9. The biocrude production system (SYS) according to any of claims 1-8, wherein the second subset comprises a setting of one or more pressure relief valves.

10. The biocrude production system (SYS) according to any of claims 1-9, wherein the hydrothermal liquefaction units (HTLU) further comprise an input storage (IST) arranged to store biomass for processing in the hydrothermal liquefaction units (HTLU).

11. The biocrude production system (SYS) according to any of claims 1-10, wherein at least one operational parameter relates to the input storage (IST).

12. The biocrude production system (SYS) according to any of claims 1-11, wherein the hydrothermal liquefaction units (HTLU) further comprise an output storage arranged to receive biocrude produced in the hydrothermal liquefaction units (HTLU).

13. The biocrude production system (SYS) according to any of claims 1-12, wherein at least one operational parameter relates to the output storage (OST).

14. The biocrude production system (SYS) according to any of claims 1-13, wherein the first subset comprises at least one parameter related to transportation of the biocrude from the output storage (OST).

15. The biocrude production system (SYS) according to any of claims 1-14, wherein the plurality of decentral hydrothermal liquefaction units (HTLU) comprises at least 3 hydrothermal liquefaction units (HTLU), such as at least 5 hydrothermal liquefaction units (HTLU), such as at least 10 hydrothermal liquefaction units (HTLU), such as at least 20 hydrothermal liquefaction units (HTLU), such as at least 50 hydrothermal liquefaction units (HTLU).

16. The biocrude production system (SYS) according to any of claims 1-15, wherein each hydrothermal liquefaction unit further comprises a pre-treatment unit for processing said biomass.

17. The biocrude production system (SYS) according to any of claims 1-16, wherein each hydrothermal liquefaction unit further comprises a depressurizing unit for depressurizing the biocrude.

18. The biocrude production system (SYS) according to any of claims 1-17, wherein each hydrothermal liquefaction unit further comprises a separation unit for separating biocrude from other components.

19. The biocrude production system (SYS) according to any of claims 1-18, wherein the wet biomass has temperature in the hydrothermal liquefaction reactor (HLR) within a range from 250 to 450 degrees Celsius, such as from 300 to 425 degrees Celsius.

20. The biocrude production system (SYS) according to any of claims 1-21, wherein the wet biomass has pressure in the hydrothermal liquefaction reactor (HLR) within a range of 50 to 400 bar, such as 100 to 300 bar.

21. The biocrude production system (SYS) according to any of claims 1-20, wherein the wet biomass has a residence time within the hydrothermal liquefaction reactor (HLR) within a range of at least 300 seconds up to 300 minutes.

22. The biocrude production system (SYS) according to any of claims 1-21, wherein the local operating system is communicatively coupled with the central monitoring facility via a communication channel.

23. The biocrude production system (SYS) according to claim 22, wherein the communication channel comprises a web service, such as the internet.

24. The biocrude production system (SYS) according to claim 22 or 23, wherein the communication channel comprises a wireless and/or a wired communication channel.

25. The biocrude production system (SYS) according to any of claims 22-24, wherein the communication channel comprises encryption means for encrypting data communications.

26. The biocrude production system (SYS) according to any of claims 1-25, wherein the system further comprises a central processing facility (CPF) for receiving one or more product streams (PST) from the hydrothermal liquefaction units (HTLU).

27. The biocrude production system (SYS) according to any of claims 1-26, wherein said one or more product streams comprises at least one of biocrude, carbon dioxide, and phosphate from the hydrothermal liquefaction units (HTLU).

28. The biocrude production system (SYS) according to any of claims 1-27, wherein the central controlling facility (CCF) is arranged to receive biocrude (BCR) from the hydrothermal liquefaction units (HTLU).

29. The biocrude production system (SYS) according to any of claims 1-28, wherein the central processing facility (CPF) comprises a biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units (HTLU).

30. The biocrude production system (SYS) according to any of claims 1-29, wherein biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units (HTLU) by lowering the viscosity of the biocrude, lowering oxygen content of the biocrude, increasing stability of the biocrude, increasing pumpability of the biocrude, increasing filterability of the biocrude, increase compatibility with oil refineries, mixing and/or homogenizing the biocrude, adapting for use as a bunker fuel, and any combination thereof.

31. The biocrude production system (SYS) according to any of claims 1-30, wherein the central processing facility (CPF) comprises a gas cleaning unit configured to clean a carbon dioxide containing gaseous fraction from one or more of the hydrothermal liquefaction units (HTLU).

32. The biocrude production system (SYS) according to any of claims 1-31, wherein the gas cleaning unit is located at the central controlling facility.

33. The biocrude production system (SYS) according to any of claims 1-32, wherein the system further comprises a solid processing unit configured to improve the quality of a phosphate containing fraction received from one or more of the hydrothermal liquefaction units (HTLU).

34. The biocrude production system (SYS) according to any of claims 1-33, wherein the solid processing unit is located at the central controlling facility.

35. The biocrude production system (SYS) according to any of claims 1-34, wherein the central processing facility (CPF) is co-located with said central control facility (CCF).

36. The biocrude production system (SYS) according to any of claims 1-35, wherein the central processing facility (CPF) comprises a biocrude processing unit configured to improve the quality of the biocrude received from one or more of the hydrothermal liquefaction units (HTLU), wherein the biocrude processing unit is co-located with said central control facility (CCF).

37. The biocrude production system (SYS) according to any of claims 1-36, wherein the hydrothermal liquefaction unit (HTLU) further comprises at least one sensor arranged to measure a process state parameter.

38. The biocrude production system (SYS) according to any of claims 1-37, wherein the hydrothermal liquefaction unit (HTLU) comprises at least one sensor arranged to measure one or more of a temperature, a pressure, and a flow parameter.

39. The biocrude production system (SYS) according to any of claims 1-38, wherein the hydrothermal liquefaction unit (HTLU) is configured to communicate said process state parameter to the central control facility.

40. The biocrude production system (SYS) according to any of claims 1-39, wherein the hydrothermal liquefaction unit (HTLU) is configured to measure and communicate said process state parameter to the central control facility automatically.

41. The biocrude production system (SYS) according to any of claims 1-40, wherein the central controlling facility is configured to control the first subset of operational parameters at least partly based on the process state parameter.

42. The biocrude production system (SYS) according to any of claims 1-41, wherein the central controlling facility is configured to automatically control the first subset of operational parameters.

43. The biocrude production system (SYS) according to any of claims 1-42, wherein the central controlling facility is configured to automatically control the first subset of operational parameters at least partly based on the process state parameter.

44. A method for operating a plurality of decentral hydrothermal liquefaction units (HTLU), the method comprising the steps of providing a biomass (BM) at each hydrothermal liquefaction unit (HTLU), pressurizing said biomass (BM) at each hydrothermal liquefaction unit (HTLU), heating said biomass (BM) at each hydrothermal liquefaction unit (HTLU), transmitting a first subset of operational parameters from a central controlling facility to each hydrothermal liquefaction unit (HTLU) operating each hydrothermal liquefaction unit (HTLU) in accordance with a set of operational parameters comprising said first subset and a second subset, wherein the second subset is controllable exclusively by a local operating system of each hydrothermal liquefaction unit (HTLU).

45. The method according to claim 44, wherein the plurality of decentral hydrothermal liquefaction units (HTLU) forms part of the biocrude production system (SYS) according to any of claims 1-43.

46. A computer program product comprising instructions that when executed by a computer processor of a central controlling facility (CCF) of the biocrude production system (SYS) according to any of claims 1-43 carries out the method according to any of claims 44-45.